This invention relates to an intake air control system for an engine and more particularly to a control valve and rectifier plate arrangement for the induction system of an engine.
As is noted in my co-pending application aforenoted, the design of the intake passage and induction system of an internal combustion engine is very important in determining its performance under all running conditions. As is also noted in that application, various devices have been proposed for inducing particular types of motion within the cylinder at least under some running conditions so as to improve mixture distribution and turbulence in the combustion chamber. However, these turbulence inducing devices should not interfere with the volumetric efficiency at high speeds.
There are disclosed in that co-pending application a number of arrangements wherein the induction system is provided with devices and valve arrangements so as to generate either swirl, swirl and tumble, tumble or no restriction depending upon the running condition of the engine. In one embodiment of that application (the embodiment of FIGS. 30 and 31), the control valve, which forms one of the main elements of the induction PG,3 system control cooperates with a rectifier plate formed in the intake passage and which rectifier plate does not substantially interfere with the flow when the control valve is open but when the control valve is closed operates to change the flow pattern entering the combustion chamber. Although that type of arrangement has a number of advantages, the construction shown in the aforenoted co-pending application also could be improved upon in some regards.
One area in which improvement was possible was in the actual cooperation between the control valve and the rectifier plate. In the aforenoted described embodiment of the co-pending application, the control valve rotates from an open position generally opposite to the direction of air flow to the position wherein the flow is redirected by the control valve and the rectifier plate. With this arrangement, there must be provided some clearance between the control valve and the rectifier plate to ensure against interference. As a result, it may not be possible to completely close off the flow through the portion of the intake passage which the control valve is designed to close.
It is, therefore, a principal object of this invention to provide an improved intake air control system for an engine that embodies a control valve and a rectifier plate.
It is a further object of this invention to provide an improved intake air control system for an internal combustion engine embodying a rectifier plate and control valve and wherein the control valve directly seals against the rectifier plate when it is in its flow controlling position.
With the arrangement shown in the aforenoted co-pending application, there must be provided some form of stop mechanism to limit the movement of the control valve in its flow controlling position. This stop mechanism is positioned generally externally of the engine and must, of course, be correctly positioned and adjusted. This has certain obvious disadvantages.
It is, therefore, a further object of this invention to provide an improved intake air control system for an engine embodying a rectifier plate and control valve and wherein the control valve engages the rectifier plate so as to limit its movement in one direction.
In the embodiment afore referred to of my co-pending application, the control valve is a generally cylindrical member having a cut away portion that is journaled for rotation in the cylinder head about an axis that is disposed transversely to the flow path of the intake charge through the intake passage and at a bight of the intake passage. With this type of arrangement, the control valve can provide a continuous intake passage surface without interruptions when it is in its open, non-flow controlling position. Because of the orientation of the components in the afore described embodiment of the co-pending application, when the control valve is in its flow restricting position, a pocket or cavity is formed in the cylinder head on the upstream side of the intake passage from the control valve. Fuel may condense and accumulate in this cavity and the cavity furthermore can create undesired turbulence in the cylinder head passage.
It is, therefore, a further object of this invention to provide an improved arrangement for the control valve, cylinder head and associated rectifier plate wherein the control valve functions to provide a continuous flow path regardless of whether the control valve is in its open position or in its flow controlling position.
When a rectifier plate is employed in conjunction with the intake passage of the cylinder head and as noted in the aforenoted co-pending application, it is necessary to separately form this rectifier plate as a part of the cylinder head, which requires a complicated casting technique, or the insertion of the rectifier plate as a separate element. That application discloses a way in which the construction can be simplified by employing a combined rectifier plate and valve seat. However, there may be some advantages in some instances in using a separate rectifier plate which then gives rise to the problem of its attachment and location within the cylinder head.
It is a further object of this invention to provide an improved rectifier plate construction for the intake port of a cylinder head wherein the rectifier plate may be formed as a separate element but may be easily held into the cylinder head without requiring additional components.
It is a further object of this invention to provide an improved arrangement wherein a rectifier plate for the intake system of an internal combustion engine cylinder head may be easily held in place by the valve seat of the cylinder head.